I would play with some friends online...so it is not very likely they will scam me (so easy) but you never know 
Well, if you are your friends are playing with just pennies it will be friendly and fun.
But once you introduce money, greed takes over. There is no way to have a fair chess game online without each person having witnesses.
It depends on your level of friendship online if it's an old friend and you know where he lives or you are both acquaintances, then you can add excitement to the game by playing for money, of course, an escrow is recommended if the amount is huge but if it's pennies then you should honor your words.